October 21st is Reptile Awareness Day. With this in mind our Object of the Month is this weird looking Rhynchosaur Skull fossil.
Rhynchosaurs, now extinct, were a kind of beaked lizard type reptile which were common 220 million years ago during the middle Triassic Period. They made up an important part of terrestrial faunas before the rise of plant eating dinosaurs near the end of the Triassic. They were about half a meter long and had a narrow, wedge-shaped skull with a few small, blunt teeth and a beak which they used to munch on rough vegetation such as ferns and horsetails.
This rhynchosaur skull fossil is from Grinshill, north of Shrewsbury. Back in the Triassic period this area of Shropshire was a hot desert on a lake margin. The rocks laid down were sand, silt and mudstones. In the late 1700s the sandstone from Grinshill began to be quarried for use in the construction of buildings in the county. This quarrying process uncovered various Triassic plant and animal fossils, including those of rhynchosaurs. Luckily, a member of the Shrewsbury Natural History Society kept a look out for these fossils during the quarrying, and many of the finds made there way eventually into the collection of Shrewsbury Museum in the 1800’s.
This particular specimen is scientifically important because it has been selected as a lectotype for the species. This means that it is the specimen with which other specimens are compared in order to name them as this species. As such, study of this specimen is ongoing. In fact, this spring it was taken for micro-CT scanning in Bristol, so researchers could study the braincase anatomy in more detail. Explore a 3D image of the rhynchosaur skull created by the Fossils in Shropshire project.
There are more rhynchosaur fossils on display in the geology gallery at SM&AG, and many reptile specimens in Shropshire Museums’ collections including turtle shells and a snake preserved in alcohol.
Object of the Month is on display in the Visitor Information Centre and features on our social media feeds: